Python生成一个不含回文字符串的字符串

class NoHuiwen(object):
    def __init__(self, _str):
        self._str = _str
        self.ret = ""

    def no_huiwen(self):
        for i in self._str:
            self.ret += i
            self.kill_huiwen(self.ret)
        print("最终结果："+self.ret)


    def kill_huiwen(self,ret):
        _len = len(ret)
        print(ret)
        if _len == 1:
            pass
        else:
            for i in range(0,len(ret)):
                _str = ret[i:len(ret)]
                print("_str:"+_str)
                if self.judge_huiwen(_str):
                    self.ret = self.ret[:-1]
                    break

    def judge_huiwen(self,_str):
        if len(_str) >= 2:
            _len = len(_str)
            if _len % 2 == 0:
                qianban = _str[0:_len//2]
                houban = _str[_len//2:_len]
            else:
                qianban = _str[0:_len//2]
                houban = _str[(_len//2)+1:_len]
            print("qianban:"+qianban)
            print("houban:"+houban)
            if qianban == houban[::-1]:
                return True
            else:
                return False
        else:
            return False


if __name__ == '__main__':
    _str = "123443absba2345467876"
    f = NoHuiwen(_str)
    f.no_huiwen()